Collapsible bit



Nov. 24,- 1931.

J. c. STOKES COLLAPSIBLE BIT Filed April 16, 1928 0 M as .y.

3110M Mob Patented Nov. 24, 193 1 JOHN C. STOKES, F HOUSTON, TEXAS, ASSI PATENT OFFICE GLiOR TO REED ROLLER BIT COMPANY, OF

HOUSTON, TEXAS, A CORPORATION OF TEXAS GOLLAPSIBLE BIT Application filed April 16,

This invention relates to deep well drilling apparatus, and more particularly to collapsible bits, and has for its general object the provision of a collapsible bit embodying new and improved means toprevent wearing of the head by cleaning'fluid and to indicate the position of the blades with respect to the head.

Fig. 1 of the drawings is a partly sectional 10 side elevation of a collapsible .bit equipped with the preferred embodiment of the invention, the carrier being shown in its lowermost position; Fig. 2, a fragmentary and partly sectional side elevation disclosing the carrier before it has reached its lowermost position;

Fig. 3, a horizontal section on the line 33 of Fig. 1; and Fig. 4, an enlarged side elevation of the liner'constituting the preferred embodiment of the invention.

The bit shown in the drawings is of the general type disclosed in my pending application for Letters Patent of the United States, Serial No. 202,990, filed June 2'Zth, 1927. The head is indicated at 1, the carrier at 2, and the blades at 3. The upper screw threaded shank 1-a of the head is adapted to be screwed into the lower section of the usual drill stem, not

shown.

The blades 3 are slidably and pivotally mounted in the fork of the carrier 2 by means of the pivot pin 4 fitting in the elongated slots 3a.

The liner provided by this invention will be found particularly useful in the bit 'ust described, but it will be understood that it may be used in bits of various types.

' Fig. 4 illustrates the liner on an enlarged scale. The upper portion 5a and the lower portion 5-c thereof have internal diameters greater than the internal diameterof the'intermediate portion 5-b. The upper portion 5-a is provided with fluid openings 5-03,

' and the intermediate portion 50Z, with fluid openings 5e. The openings 5e are somewhat larger than the openings 5d. A blade engaging element is disposed at the lower end of the liner. This element may be in the form of a ring 6 integral with or separable from the liner 5, and L-shaped in cross-section.

Referring now to Fig. 1,'the head has in 1928. Serial m. 270,238.

the lowermost portion thereof an internal annular flange 1Z). The ring 6 of the liner rests upon this flange. The head has an internal annular groove 1-0 and fluid courses 1-e communicating with said groove. The openings 5.el and 5 e in the liner 5 are disposed opposite the groove 1c, as shown. The upper part 'of carrier 2 is reduced as indicated at 2a.

Collapsible bits have heretofore been provided having a head with courses therein through which cleaning fluid is pumped, and a carrier slid-able in the head and adapted to prevent or limit the passage of cleaning fluid into the courses until the blades have swung outwardly into an operative position. The driller observing the resistance encountered .by the cleaning fluid pump can thereby ascertain whether the blades are so disposed that drilling may be commenced. My'pending application hereinabov identified covers the type of bit illustrated in the drawings. In

' the use of said bit, it has been found that the cleaning fluid, which is ordinarily muddy water or the like known as slush, rushes between the carrier 2 and the head 1 into the groove 1 c and cuts away the head.

The liner 5 provided by this invention prevents this wearing of the head. The cutting action of the slush'is such that the liner itself is'worn away, but as it is removable, a new liner may quickly and easily be substituted. and the head used for a great length of time. Referring to Fig. 2, it will be seen that the carrier 2 does not close the upper openings 5-111 even when the blades are not in an operative position, because the carrier fits loosely in the upper portion 5a of the liner and fluid may pass therebetween. The reason for this is that the fluid passages through the head should never be totally closed. Should the stem become stuck in the hole, slush may be pumped through the head and up around the stem to remove the gripping formation. But the lower openings 5e, which are larger than the upper openings 5cl, are closed by the carrier until the blades swing outwardly. The carrier snugly fits the intermediate portion 5*?) of the liner, and prevents the passage of fluid therebetween.

And sothe variance of the resistance offered the pump will be indicative of the disposition of the blades. Should anything prevent the assumption by the blades of an operative position, the carrier cannot move downwardly to open the openings 5e.

It will be understood that the shoulders 3-6 of the blades will engage the ring 6 and that downward movement of the carrier after such engagement will permit the passage of fluid through the openings 5e and swing the blades into an operative position, when drilling may be commenced.

I claim:

1. In acollapsible bit, the comb nation with a head having a fluid course therein, and a carrier slidable in said head, of a liner shaped to fit between said head and carrier and having an opening communicating with said course.

2. In a collapsible b t, the combination with a head having a fluid course therein, and a carrier slidable in ,said head, of a liner shaped to fit between said head and carrier, and having fluid openings in the side thereof disposed one above the other.

3. In a collapsible b t, the combination with a headhaving a fluid course therein, and a carrier slidable in said head, of a liner shaped to fit between said head and carrier, and having large and small fluid openings therein communicating with said course.

4. In a-collaps ble bit, the combination with a head having a fluid course therein, and a carrier slidable in said head, of a liner shaped to fit between said head and carrier, said liner having one portion with an internal diameter greater than the internal diameter of another portion, and fluid openings insaidport ons.

5. In a collapsible bit, the combination with a head having a fluid course therein, and a carrier slidable in said head, of a liner shaped to fit between said head and carrier, said liner having one portion w th an internal diameter greater than the internal diameter of another portion, a large fluid opening in said one portion, and a small fluid opening in said another portion. I

6. In a collaps ble bit, the combination w th a head and a carrier slidable therein and having a reduced upper portion. of a liner shaped to fit between said head and carrier and havin a fluid opening in the side thereof.

I. A liner compris ng a cylindrical body having a fluid opening in the side thereof and a blade-engaging ring L-shaped in cross-section.

8. A collapsible bit liner having a body portion, an end portion having an internal diameter greater than theinternal diameter of the body portion, and a wear ring coextensive with said end, said ring being L-shaped in cross-section.

9. In a collapsible bit, the combination with a head having a fluid course therein, a

carrier slidable in said head, and collapsible blades on said carrier, of a liner, said liner being shaped to fit between said head and carrier and having a fluid opening therein communicating with said course, and having an element to engage said blades.

10. In a collapsible bit, the combination with a head having an internal annular groove and a fluid course communicating with said groove, and a carrier slidable in said head, of a liner shaped to fit between said head and carrier and having a plurality of openings in the side thereof communicating with said oove.

11. In a co lapsible bit. the combination with a head'having a fluid course therein, and a carrier slidable in said head, of a liner shaped to fit between said head and carrier, said liner having a fluid opening therein communicating with said course, collapsible blades on said carrier, and means on "said liner to engage said blades to swing the same into an operative position, said carrier preventing the passage of fluid through said opening until said means swings said blades. 12. In a collapsible bit. the combination with a head having a fluid course therein, a carrier slidable in said head, and a blade on said carrier, of a liner between said head and said carrier and having fluid openings therein. one above the other communicating with said course, one of said openings being substantially closed by said carrier when said carrier is not in a position to support said blade in its operative position, and being open when said carrier is in said pos tion.

13. In a collapsible bit, the combination with a head having a fluid course therein, a carrier slidable in said head, and a blade on said carrier, of a liner between said head and said carrier and having large and small openings communicating with said course, saidlarge opening being substantially closed by said carrier when said carrier -is not in a position to support said blade in its operative osition, and eing open when said carrier is in said position. i

14. In a collapsible bit, the combination with a head having a fluid course therein, a carrier slidable in said head, and a blade on said carrier, of a liner between said head and carrier and having portions of different internal diameters and fluid openings in said portions communicating with said course, the opening in that portion of smaller diameter being substantially closed by said carrier when said carrier is not in a position to suport said blade in its operative position, and eing open when said carrier is in in said position.

In testimony whereof, I hereunto afiix my signature.

JOHN C. STOKES. 

